In the mesohyl of various undisturbed sponges, one is likely to observe (at one time or another) all of the following except A) amoebocytes. B) spicules. C) spongin. D) zygotes. E) choanocytes.

E

Which chemical is not normally found in any sponges? A) chitin B) spongin C) calcium carbonate D) silica E) cribrostatin

A

) Which of these factors, when used to label the horizontal axis of the graph in Figure 33.1, would account most directly for the shape of the plot? A) spongin concentration (gm/unit volume) B) rate of cribrostatin synthesis (molecules/ unit time) C) number of amoebocytes per sponge D) number of spicules per sponge E) number of choanocytes per sponge

E

In terms of food capture, which sponge cell is most similar to the cnidocyte? A) amoebocyte B) choanocyte C) gamete D) epidermal cell E) pore cell

All of the following are characteristics of the phylum Cnidaria except A) a gastrovascular cavity. B) a polyp stage. C) a medusa stage. D) cnidocytes. E) a pseudocoelom.

E

) What is the best way to describe the brain of a sea anemone? A) a thick ring around the mouth B) a series of ganglia at the base of the tentacles C) a pair of ganglia at the anterior end D) a single ganglion in the body wall E) nonexistent

E

Which of the following is a correct statement about members of the phylum Cnidaria? They A) are not capable of locomotion because they lack true muscle tissue. B) are primarily filter feeders. C) have either or both of two body forms: mobile polyps and sessile medusae. D) may use a gastrovascular cavity as a hydrostatic skeleton. E) are the simplest organisms with a complete alimentary canal (two openings).

D

The members of which class of the phylum Cnidaria occur only as polyps? A) Hydrozoa B) Scyphozoa C) Anthozoa D) Cubozoa E) both B and D

C

Which class of the phylum Cnidaria includes "jellies" with rounded (as opposed to box-like) medusae? A) Hydrozoa B) Scyphozoa C) Anthozoa D) Cubozoa E) Both A and C are referred to as "jellies."

In a small stream, you pick up a rock and observe many small, flattened worms crawling on its undersurface. You decide that they belong to the phylum Platyhelminthes. To which class do they probably belong? A) Cestoda B) Monogenea C) Turbellaria D) Trematoda E) Hirudinea

C

What would be the most effective method of reducing the incidence of blood flukes in a human population? A) Reduce the mosquito population. B) Reduce the freshwater snail population. C) Purify all drinking water. D) Avoid contact with rodent droppings. E) Carefully wash all raw fruits and vegetables.

B

) The larvae of many common tapeworms affecting humans are usually found A) encysted in human muscle. B) encysted in the muscle of an animal such as a cow or pig. C) in the abdominal blood vessels of humans. D) in the human brain. E) in the intestines of cows and pigs.

B

While vacationing in a country that lacks adequate meat inspection, a student ate undercooked ground beef. Sometime later the student became easily fatigued, and lost body weight. At about the same time, whitish, flattened, rectangular objects full of small white spheres started appearing in his feces. Administration of niclosamide cured the problem. The student had probably been infected by a A) pinworm. B) hookworm. C) nematode. D) tapeworm. E) proboscis worm.

D

) Which of the following statements about Cestoda feeding methods is false? A) They lack a digestive tract. B) They use a degenerate mouth to ingest some of their food. C) As adults, they live in a digestive tract. D) They are parasites. E) They absorb nutrients through the walls of their body.

B

All of the following characterize the phylum Rotifera except A) a complete digestive tract. B) a crown of cilia at the anterior end that resembles a wheel. C) parthenogenic reproduction. D) a life cycle stage that is resistant to desiccation. E) a relatively large size.

E

A lophophore is used by ectoprocts, phoronids, and brachiopods A) for locomotion. B) at a larval stage. C) for feeding. D) for sensory reception. E) as a skeletal system.

C

A brachiopod can be distinguished from a bivalve by the presence of A) two hinged shells. B) a digestive system with separate mouth and anus. C) a lophophore. D) suspension feeding. E) a distinct head.

C

While sampling marine plankton in a lab, a student encounters large numbers of fertilized eggs. She rears some of the eggs in the laboratory for further study and finds that the blastopore becomes the mouth. The embryo develops into a trochophore larva and eventually has a coelom. These eggs probably belonged to a(n) A) annelid. B) echinoderm. C) mollusc. D) nematode. E) arthropod.

A radula is present in members of which class(es)? A) Gastropoda B) Polyplacophora C) Bivalvia D) A and B only E) A, B, and C

D

While snorkeling, a student observes an active marine animal that has a series of muscular tentacles bearing suckers associated with its head. Segmentation is not observed, but a pair of large, well-developed eyes is evident. The student is observing an animal belonging to which class? A) Gastropoda B) Cephalopoda C) Polyplacophora D) Polychaeta E) Bivalvia

B

Which of the following is not found in annelids? A) a hydrostatic skeleton B) segmentation C) a digestive system with separate mouth and anus D) a closed circulatory system E) a cuticle made of chitin

E

A. Oligochaeta B. Polychaeta C. Hirudinea D. two of the above E. all of the abovehave parapodia

B

A. Oligochaeta B. Polychaeta C. Hirudinea D. two of the above E. all of the above) many are parasites

C

A. Oligochaeta B. Polychaeta C. Hirudinea D. two of the above E. all of the above) have segmented bodies

E

A. Oligochaeta B. Polychaeta C. Hirudinea D. two of the above E. all of the above) make castings that are agriculturally important

A

A. Oligochaeta B. Polychaeta C. Hirudinea D. two of the above E. all of the above) name indicates the relative number of bristles its members have

D

A. Oligochaeta B. Polychaeta C. Hirudinea D. two of the above E. all of the above

some members release an anticoagulate that is of medical significance

C

Which of the following is not characteristic of nematodes? A) They play an important role in decomposition. B) They have both circular and longitudinal muscles. C) They have a pseudocoelom. D) They have an alimentary canal. E) Many species are parasitic.

All of the following can be used to distinguish a nematode worm from an annelid worm except A) type of body cavity. B) number of muscle layers in the body wall. C) presence of segmentation. D) number of embryonic tissue layers. E) presence of an alimentary canal.

D

Nematode worms and annelid worms share all of the following features except A) use of fluid in the body cavity as a hydrostatic skeleton. B) use of the outer covering as a respiratory surface. C) presence of a closed circulatory system. D) presence of an alimentary canal. E) parasitic lifestyles in some species.

C

A student observes a worm-like organism crawling about on dead organic matter. Later, the organism sheds its outer covering. One possibility is that the organism is a larval insect (like a maggot). On the other hand, it might be a member of the phylum ________. One way to distinguish between the two possibilities is by looking for the presence of A) Platyhelminthes; a cuticle of chitin. B) Nematoda; an alimentary canal. C) Annelida; a body cavity. D) Nematoda; a circulatory system. E) Annelida; muscle in the body wall.

D

The heartworms that can accumulate within the heart of dogs and other mammals have a pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong? A) Platyhelminthes B) Arthropoda C) Nematoda D) Phoronida E) Annelida

Skeletal structures that are entirely or partly composed of calcium carbonate can be found in some members of the following except A) sponges. B) coral animals. C) molluscs. D) arthropods. E) nematodes.

E

) An arthropod has all the following characteristics except A) protostome development. B) bilateral symmetry. C) a pseudocoelom. D) three embryonic germ layers. E) an open circulatory system

C

All of the following are characteristics of adult arthropods except A) an exoskeleton. B) hemolymph. C) jointed appendages. D) a heart. E) a coelom.

The presence or absence of mandibles can be used to distinguish between A) insects and centipedes. B) insects and crustaceans. C) insects and millipedes. D) insects and spiders. E) centipedes and millipedes.

D

) A shared derived characteristic for members of the arthropod subgroup that includes spiders would be the presence of A) chelicerae. B) an open circulatory system. C) an exoskeleton. D) a cuticle. E) a cephalothorax.

A

) You find a small animal with eight legs crawling up your bedroom wall. Closer examination will probably reveal that this animal has A) antennae. B) no antennae. C) chelicerae. D) A and C E) B and C

E

While working in your garden, you discover a worm-like, segmented animal with two pairs of jointed legs per segment. The animal is probably a A) millipede. B) caterpillar. C) centipede. D) polychaete worm. E) sow bug.